Visible light is used to perform data transmission in visible light communication. Compared with microwave technologies, the visible light communication has abundant spectrum resources, which is incomparable with general microwave communication and wireless communication. Meanwhile, the visible light communication is applicable to any communications protocol, and is suitable for any environment. In addition, signal coverage of the visible light communication can be controlled easily, and communication content can hardly be intercepted and has relatively high security. Furthermore, a visible light communication device features flexibility and convenience with low costs, and is applicable to large-scale popularity and application.
Currently, signal transmission mainly uses white light or monochromatic light to perform light signal transmission. However, if light signals of a same color are used in uplink and downlink transmission, reliability of received light signals may be affected. For example, a transmit/receive device transmits a white light signal in the uplink and receives a white light signal in the downlink. In this case, when receiving the white visible light signal in the downlink, the light signal transmission device may be affected by the white light signal emitted by itself.
In addition, the light communications technology is a new technology that uses a fluorescent lamp, a light emitting diode LED, or the like that sends high-speed dark and dim-flashing signals invisible to eyes to transmit information, and provides different 1 and 0 sequences by changing a rate at which an LED is turned on or off, so as to encode data and perform data transmission in free space. Then encoding is performed after data is received by a light receiver on a receiving end, to restore information such as original data.
In an existing technology, since a light flashing manner is used to transmit signals, and there is only one path for an air channel, after sampling and an analog-to-digital conversion are performed on each input signal, a light signal transmitting end can send each input signal only through a single air channel. Even if a light signal receiving end has dual channels for output, and a play device can receive signals from dual channels and play through dual channels, a signal finally output to the play device can only be a single-signal because received light input is in only one channel.
For example, a wireless photonic conference system, as an application of the visible light communications technology, adopts visible light to transmit an audio signal. The wireless photonic conference system includes a light signal transmitter and a light signal receiver, which are connected in a wireless manner. The light signal transmitter can convert audio information, transferred from a microphone, to one serial digital signal; modulate the signal to an LED; and send the signal through the LED. The light signal receiver can receive a light signal from an LED, convert the light signal to an electrical signal, and convert the electrical signal to an analog audio signal through a digital-to-analog conversion, so as to drive a play device, such as a headphone, to play sound. By using light transmission of the photonic conference system, wireless transmission of the audio signal is implemented. However, after sampling and an analog-to-digital conversion are performed on each type of input audio signal by the light signal transmitter, the audio signal can be transmitted only through a single air channel; therefore, light input received by the light signal receiver can be only an audio signal of a single sound channel, and only sound of a single sound channel can be played even if a sound play device has a dual-sound channel stereo function.
With regard to the problems in a related technology, no effective solution is provided as of now.